Put first 7 ingredients in blender and process to a puree (use some of the broth if necessary).
Add this puree to the rest of the broth in a wide heavy based pan (you will be poaching fish in this pan), bring to a boil, lower heat and simmer 5 minutes.
Taste now for seasoning, adding salt/soy if necessary.
Optional Extra Step: Sear fish pieces in a separate very hot saute pan in some butter or oil-no more than 30 seconds each side (This adds color and flavor, but isn't strictly necessary).
Add fish pieces to simmering (it should be bubbling when you add fish) liquid and poach on slightly lowered heat, turning once, about 5 to 8 minutes total (depends on type and thickness of fish and if you have seared it).
Do not overcook!
Remove fish and serve in a platter, with sauce poured over the fish.